WASHINGTON — Most politicians are as likely to pass up free TV face time before an election as they would be to refuse a campaign check.

Then again, there's a price to be paid for looking stupid.

That's what members of Congress have learned recently about "Better Know a District," a sarcastic weekly skit that is part of "The Colbert Report," a nightly half-hour on Viacom Inc.'s Comedy Central network.

Hosted by comedian Stephen Colbert, the year-old program is a spinoff of the cable channel's wildly popular "The Daily Show Starring Jon Stewart" and one of an increasing number of political humor shows on cable that are drawing the young viewers whom advertisers covet.

Politicians covet them too for their votes. So, many lawmakers initially played along with the segments in which Colbert interviews a member of the House of Representatives, with few checks and balances on his proclivity to make fools of them.

But after a couple of House members stumbled badly on the show, some incumbents decided that the dumbest thing to do with Colbert's offer of free TV exposure was to take it.

"I watch it all the time," said House Minority Leader Nancy Pelosi (D-San Francisco), "and I think, 'Why would anybody go on there?' "

With polls showing that the balance of power in Congress could shift from Republican to Democrat in next month's elections, few incumbents are in the mood to take chances. Indeed, it's been two months since a current member has appeared.

One who did appear, Rep. Lynn Westmoreland (R-Ga.), discovered the pitfalls when Colbert asked him about a bill he co-sponsored requiring that the Ten Commandments be displayed in the U.S. Capitol.

"What are the Ten Commandments?" Colbert asked matter-of-factly.

"What are all of them?" Westmoreland said, taken aback. "You want me to name them all?"

The June segment showed Westmoreland struggling to name just three. Westmoreland actually named seven, said his press secretary, Brian Robinson. And the remaining ones, he added, were somewhat obscure.

A Bible Belt conservative, the embarrassed Westmoreland has been trying to live down his Commandments performance. No Republican has appeared since.

Negative phone calls from around the country poured in to Westmoreland's office, mostly from liberals charging hypocrisy, Robinson said. Several clips of the segment are posted on the YouTube website, and Westmoreland's Democratic opponent, Mike McGraw, put the video on his campaign website.

"It's a great thing to do if all Americans had a sense of humor," Robinson said of a Colbert appearance. "Unfortunately, some don't get the joke."

What really got the attention of House members was the experience of Rep. Robert Wexler (D-Fla.). Colbert told him he was free to make even the most outrageous statements because he was running for reelection unopposed. Then Colbert coaxed Wexler into a spoof declaration that he enjoyed cocaine and prostitutes because "it's a fun thing to do."

Several media outlets trumpeted Wexler's comments without making it clear that he was only answering Colbert's fill-in-the-blank questions.

"I'm going to try to keep my day job and not go into comedy," Wexler said, although he noted that the reaction from his constituents was overwhelmingly positive.

Wexler's gaffe, following Westmoreland's trouble, has made some legislators gun-shy about facing Colbert with elections approaching. Colbert and the show's staff have declined media interviews about the segments since the Wexler episode.

But ignoring Colbert has its own perils.

When Rep. Sue W. Kelly (R-N.Y.) declined to appear for the segment that aired Thursday night, Colbert invited her Democratic opponent, John Hall.